<template>
    <router-link custom v-slot="{navigate}" to="/" >
        <div class="header-abs" @click="navigate" v-show="this.showAbs">
            <div class="iconfont back-icon">&#xe613;</div>
        </div>
    </router-link>
    <div class="header-fixed" v-show="!this.showAbs" :style="opacityStyle">
        景点详情
        <router-link to="/">
            <div class="iconfont header-fixed-back">&#xe613;</div>
        </router-link>
    </div>
</template>

<script>
export default {
    name: 'DetailHeader',
    data () {
        return {
            showAbs: true,
            opacityStyle: {
                opacity: 0
            }
        }
    },
    methods: {
        handleScroll() {
            const top=document.documentElement.scrollTop
            if( top > 60){
                let opacity = top/140
                opacity = opacity >1 ? 1 : opacity
                this.opacityStyle.opacity=opacity
                this.showAbs=false
            }else{
                this.showAbs=true
            }
        }

    },
    activated() {
        window.addEventListener('scroll',this.handleScroll)
    },
    deactivated(){
        window.removeEventListener('scroll',this.handleScroll)
    }
}
</script>

<style lang="stylus" scoped>
@import '../../../assets/styles/varibles.styl'
    .header-abs
        position absolute
        left .2rem
        top .2rem
        width .8rem
        height .8rem
        line-height .8rem
        border-radius .4rem
        text-align center
        background-color rgba(0,0,0,.8)
        .back-icon
           color #fff
           font-size .4rem
    .header-fixed
        z-index  2
        position fixed
        top 0
        right 0
        bottom 0
        left 0
        height $headerHeight
        line-height $headerHeight
        text-align center
        color #fff
        background $bgColor
        .header-fixed-back
           position absolute
           top 0
           left 0
           width .64rem
           text-align center
           font-size .4rem
           color #fff
</style>